laststop311 :
They are using a desktop gtx 760 and not a mobile gtx 760m correct? The GTX 760 is just the right amount of value to performance ratio for gaming at 1920x1080. It will currently play probably 99% of games at ultra details and 1080p. But it isn't a very future proof solution. In the coming years some games that come out may need the detail level backed down from ultra to high. My issue with the system is they are probably going to charge a huge premium for the design that went into making it so small. Also these small gaming system are notorious for having fans that have to run at very high rpms to keep everything cool, meaning LOUD.
Yes it's small but you can make a mini itx system that is still relatively small to most gaming pc's and have a cheaper, quieter higher performing gaming PC than this BRIX. And if u can stand to go a little larger micro atx systems are currently the cheapest to build. Still a lot of price premiums for mini itx sized components. You will get the most performance for your dollar building a micro atx gaming system.
Actually they are using an undervolted and under clocked desktop gtx 760 according to Hexus
http://hexus.net/tech/news/systems/71457-gigabyte-announces-brix-gaming-diy-pc-kit/
this is probably the slim gtx 760 that MSI sells currently that is under clocked and undervolted. And yes even if it is undervolted and under clocked at worst it would perform around the 650 ti boost level of performance witch is just slightly less than a gtx 660. Having owned both the ti boost and the 660, I can say they are both completely competent gaming cards in their own right.
As for the CPU, the i5 4200u is just a hair slower than the i3 3220 which my older sister currently owns, and can recommend to any gamer with a budget, as the B word (bottleneck) is true in synthetic benchmarks, she has not found a game she cannot play on her 660 and i3 at high without dipping below 30fps including Metro Last Iight and crysis on high settings at 1080p
http://cpuboss.com/cpus/Intel-Core-i5-4200H-vs-Intel-Core-i3-3220
The only real downfall I see here is that the two small fans could get very loud when playing games as you said, I personally don't care too much for a noisy pc as I like to know that my computer is working (one of my silent fans on my coolermaster 212 evo went out about 7 months ago, and made my pc do an emergency shutdown to avoid frying my cpu, temp log showed it reached 115C before it shut down) but these could reach mini RC helicopter noise levels which could be annoying if you are not wearing a headset. Then the price point, if Gigabyte manages to keep this thing below $450 (it wont be) then they have a capable gaming bare bones system to sell. After buying the OS, and HDD, and 8gb of SODIMMS and maybe an ssd if budget is no concern, it comes out to be around $650-$700. It will have a price premium to be sure, but ill wait and see what the i7 version costs